Preparation of cationic waterinsoluble phenol-formaldehyde condensation products containing omega-sulfonic acid radicals



' Parental July as, .1949.

PREPARATION OF CATIONIC WATER- INSOLUBLE PHENOL-FORMALDEHYDECONDENSATION PRODUCTS CONTAIN- lNG OMEGA-SULFONIC ACID RADICALS HaroldM. Day, Cos Cob, Coma, assignor to American Cyanamid Company, New York,N. Y a

corporation of Maine No Drawing. Application November 27, 1946,

Serial No. 712.741

Claims. (Cl. 260-49) This invention relates to cation active syntheticresins and more particularly, to an im- Proved process for themanufacture of cation active synthetic resins prepared. from phenol,formaldehyde. and an alkaline sulfiting agent.

It is well known to the art that phenol, its homologues or its alkalimetal salts may be condensed with formaldehyde and then treated with asulflte, a bisulflte or other suliurous acid derivative or that it maybe treated with the sulfurous acid derivative concurrently withcondensation with formaldehyde to produce a cation active resin.Products of this type are, for example, descrlbed in U. S. Patent No.2,228,159.

It is an object of the present invention to provide a process forpreparing cation active synthetic resins of improved properties fromphenol, formaldehyde and an alkaline water-soluble salt of sulfurousacid. 1

It is a further object of the present invention to prepare a resin fromphenol, formaldehyde, and an alkaline water-soluble salt of sulfurousacid, said resin having agood density and a high capacity for theremoval of cations from, or the exchange of cations in, liquid media.

These and other objects are attained by bringing about reaction betweenphenol, formaldehyde and an alkaline water-soluble salt of sulfurousacid in the presence of a maximum of about 40% by weight of waterfollowed by curing the resulting resinous syrup at temperatures aboveThe present invention will be described in greater detail in conjunctionwith the following specific examples in which the proportions are given"in parts by weight. These examples are merely illustrative and it is notintended that the scope or the invention be restricted to the detailstherein set forth.

Exmns 1 l Parts Anhydrous phenol (1.0 mol) 94 Anhydrous sodium bisulflte(0.25 mol) 26 Anhydrous sodium suliite (0.25 mol) 31.5 Para-formaldehyde(2.5 mols) 75 Water I 11.3

and cured at c. followed by additionalheating for 16 hours at C. l Theresin is then ground and upon evaluation of the 24-30 mesh material,found to have a capacity for the removal of cations from solution of17.8kilograins as calcium carbonate per cubic foot of resin, a packedvolume of 26.0 cc. and a density of 25.3

lbs./cu. ft.

Exams: 2

Parts Anhydrous phenol (1.0 mol) 94 Anhydrous sodium bisulflte (0.25mol) 26 Anhydrous sodium sulflte (0.25 mol) 31.5 37% formalin (0.63) molas HCHO) 50.6

Para-formaldehyde (1.87 mols as HCHO) 56.2

ing for 16 hours atf150", C. The resin is then ground and uponevaluation of the 24-30 mesh material, found to have a capacity for theremoval of cations from solution of 18.9 kilograms as calcium carbonateper cubic foot of resin, a packed volume of 27.0 cc. and a density of 26lbs/cu. ft.

Exiurrnn 3 Parts Anhydrous phenol (1.0 mol) 94 Anhydrous sodiumbisulilte (0.25 mol) 26 Anhydrous sodium sulflte (0.25 mol) 31.5

37% formalin (1.25 mols as none) 101 Para-formaldehyde (1.25 molsasHCHO)37.5

The procedure of Example 2 is followed, the

initial reaction mixture containing 22% by" weight of water. The resinobtained has a capacity for the removal of cations from solution of 19.8kilograins calcium carbonate per cubic footof resin, a packed volume of25.500. anda density of 24.3 lbs/cu. ft.

Exlmrns 4 l Parts Anhydrous phenol (1.0 mol) 94 Anhydrous sodiumblsulflte (0.25 mol) 26 Anhydrous sodium sulfite (0.25 mol) 31.5 37%formalin (2.5 mols as HCHO) 202.5

The procedure of Example 2 is followed the initial reaction mixturecontaining 36% by Experiment 1 Parts Anhydrous phenol (1.0 mol) 94Anhydrous sodium blsulflte (0.25 mol) 26 Anhydrous sodium sulflte (0.25mol) 31.5 37% formalin (2.5 mols as HCHO) 1202.5 Water 50 The procedureof Example 2 is followed, the initial reaction mixture containing 44% byweight of water. The resin obtained has a capacity for the removal ofcations from solution of 15.3 kilograins as calcium carbonate per cubicfoot of resin, a packed volume of 26.5 cc. and a density of 18.1lbs./cu. ft.

Experiment 2 Parts Anhydrous phenol (1.0 mol) 94 Anhydrous sodiumbisulflte (0.25 mol) 26 Anhydrous sodium sulflte (0.25 mol) 31.5 37%formalin (2.5 mols as HCHO) 202.5 Water 100 The procedure of Example 21sfollowed, the initial reaction mixture containing 50% by weight ofwater. The resin obtained has at capacity for the removal .of cationsfrom solution of 15.3 kilograms calcium carbonate per cubic foot ofresin, a packed volume of 27.0 cc. and a density of 19.8 lbs/cu. ft.

Experiment 3 Parts Anhydrous phenol (1.0 mol) 94 Anhydrous sodiumblsulilte (0.25 mol) 26 Anhydrous sodium sulflte (0.25 mol) 31.5 37%formalin (2.5 mols as ECHO) 202.5 Water 150 The procedure of Example 2is followed. the

initial reaction mixture containing 55% by weight of water. The resinobtained has a capacity for the removal of cations from solution 1 of14.3 kilograins calcium carbonate per cubic foot of resin, a packedvolume of 27.0 cc. and

a density of 17.2 lbs/cu. ft. of resin.

It will be apparent from the foregoing experiments and examples thatcareful control of the water content of the initial reaction mixturecontaining phenol, formaldehyde and sulfurous acid derivative produces aminimum of about a 12% increase in capacity and a increase in densityand a maximum of about a 28% increase in capacity and a 35% increase indensity.

In general, I prefer the use of reaction mixtures containing from about5% to about 40% by weight of water in the process of the presentinvention. However, while the upp r limit is critical and no more than40% water may be present without a resin of inferior propertiesresulting, the lower limit of 5% is flexible and under carefullycontrolled conditions the water content of the reaction mixture may bedropped down to substantially zero without any accom- '4 patnying lossin'quality of the desired resin produc Exam 5 Parts Anhydrous phenol(1.0 mol) 94 Anhydrous sodium bisulflte (0.25 mol) 26 Anhydrous sodiumsulflte (0.25 mol) 31.5

37% formalin (2.5 mols as HCHO) 202.5

The procedure of Example 2 is followed except that the viscous syrup iscured by heating for 5 hours at C. and 16 hours at 150 C. The curedresin has a capacity for the removal of cations from solution-of 16.1kilograms calcium carbonate per cubic foot of resin, a packed.

volume of 25.0 cc. and a density of 19.7 lbs/cu.

ft. of resin.

Example 6 Ingredients as listed in Example 5 are combined according tothe details of Example 2 except that the viscous syrup is cured byheating for 6 hours at 100 C. and for 8 hours at C. The cured resin hasa capacity for the removal of cations from solutions of 15.4 kilogramscalcium carbonate per cubic foot of resin, a packed volume of 22.0 cc.and a density of 19.6 lbs/cu. ft. of resin.

In order to illustrate the criticality of the cur ing temperature in thepreparation of sulfonated phenol-formaldehyde cation exchange resins ofsuperior properties the following experiment was run for purposes ofcomparison:

Experiment 4 Parts Anhydrous phenol (1.0 mol) 94 Anhydrous sodiumbisulilte (0.25 moi) 26 Anhydrous sodium sulflte (0.25 mol) 31.5

37% formalin (2.5 mols as HCHO) 202.5

The procedure of Example 2 is foliowed except that the resin is cured byheating for 18 hours at 100C. Upon evaluation it is found to have acapacity for the removal of cations from solution of 13.8 kilograinscalcium carbonate per cubic foot of resin, a packed volume of 25.5 cc.and a density of 18.6 lbs/cu. ft. of resin.

By comparison of the results. of Examples 5 and 6 with those ofExperiment 4 above, it will be apparent that curing at a temperatureabove 100 C., i. e., about 125-150 0., affects about a 10%-14% increasein the capacity of the cured resin.

Any alkaline water -soluble salt of sulfurous acid may be used in theprocess of the present invention. Such salts include metal salts, forexample other alkali metal sulfites such as potassium sulflte, alkalimetal bisulfltes such as sodium metabisulflte, sodium bisulflteliquor,potassium bisulfite, etc., tertiary amine salts, for example, triso,

methylamine sulfite, etc., and quaternary ammonium salts, for examplebenzyl trimethyl ammonium bisulfite, etc. It will be apparent thatmixtures of two or more of the sulfurous acid derivatives of the typelisted above may be utilized in place of any single agent.

. I prefer a molar ratio of formaldehyde to phenol of about 2.5:1, butthe invention is in no sense limited to this particular proportion. Moreformaldehyde generally produces a resin of no higher capacity while lessformaldehyde mayresultin a' more water-soluble product. In general,ratios of from about 2:1 to about 5:1, formaldehydejto phenol, may beutilized. 1

I prefer to react the phenol and the sulfurous acid derivative in abouta 1:05 molar ,ratio. If

' airman more sulfite, lei-example, is used the resulting resin has atendency to swell and if less sulilte is used theresulting resin mayhave a lower capacity. However, the invention is inno'sense restrictedto-this particular proportion andmolar ratios of irom about 1:1 to about1:0.25, phenol to water-soluble sulfurous acldsalt, may be used.

At leastone molar proportion of formaldehyde must be reacted with thephenol before it is sulfonated since presumably only one of the methylolgroups is sulionated in the final resin. Evidencefor this is therecovery of one mole of sodium hydroxide for each mole of phenol reactedwith sodium sulflte. Accordingly, it is possible within the scope of thepresent invention to condense the phenol, formaldehyde and sulfurousacid salt simultaneously or to condense the phenol with excessformaldehyde and then treat the resulting condensation product with thesalt. If desired, something less than the total amount of formaldehydebut at least an equimolar quantity thereof may be precondensed with thephenol, that condensation product treated with a sulfurous acidderivative, and the sulfonated product. then resiniiled with theremainder of the formaldehyde.

It is essential to the production of cation exchange resins of improvedproperties according to the process of the present invention that our--ing be eil'ected at high temperatures, 1. e., about 125-1'l5 C. If theresin is finally cured at a lower temperature it has a tendency to swelland, in addition, as is demonstrated by Experiment 4, it has a lowercapacity for the removal of cations from liquid media. It is desirableto procure the resins at a lower temperature, i. e., about 100 C.,

in order to avoid the putting which may occur if they are subjectedinitially to the high curing temperature. After this pre-curing however,there is no particular advantage gained in grinding the procured resinbefore final curing since the resin so obtained usually does not have asood a capacity as one which is not ground between the precuring andfinal curing steps.

A resin of higher capacity is obtained after the reduction freealkalinity due to the molar equivalent of alkali liberated in thereaction for every mole of sulfite used. In the foregoing examples thisalkalinity has been reduced by utilization of a mixture of bisuliite andsulflte. This may also be accomplished by neutralization of the resinwith an acid wash prior to curing.

The sulfur of the sulfonate group is attached to an aliphatic carbonatom in the final resin; there is no nuclear sulfonation takin placeunder the conditions of the reaction.

It is an advantage of the present invention that the granular,water-insoluble synthetic resins produced in accordance therewith arecapable of exchanging cations in. liquid media and of removing cationsirom liquid media. In this connection, my resinous materials may be usedin admixture with other cation active materials or they may be usedalone. Furthermore, my resins may be applied before gelation to asuitable carrier such as diatomaceous earth, clay, charcoal, etc. Inthis way, the active resin is spread on the surface of a relativelyinert material and one is thus enabled to employ a smaller quantity ofresin than otherwise to obtain the same active area.

Resinous materials prepared according to my invention are useful in theremoval of cations from fluid media, especially aqueous solutions. Theresins may be used in the hydrogen-activated form to remove cations fromsolutions of bases. and they may also be employed as exchange materialsin accordance with the principles applied to the use of the-natural andsynthetic zeolites.

Thus, the resin may be activated with a sodium salt such as sodiumchloride and upon contact with a solution containing calcium, magnesiumor other similar cation, an exchange of the latter ions for the sodiumions takes place.

The activating solutions or regenerating solutions for my resins aredilute acid solutions or dilute salt solutions, e. g., about 0.2%-10% o!suliuric acid, hydrochloric acid, sodium chloride. potassium chloride,etc.

To be sumcient insoluble for practical use in the art of waterpurification, a resin should have a sufilciently low solubility that itwill not be dissolved away rapidly by the solution to be treated. Thus,water should not dissolve more than about 1 part of resin in 1,000 partsof water when passed through a bed of resin after the first cyclecomprising an activation, exhaustion and reactivation of the resin.

It is preferable to grind and screen the resins to a particle size offrom about 8-60 mesh. Use

of larger particles causes channeling, and smaller particles of resinhave been found to pack, thus reducing the cation exchange efllciency ofthe material.

My resinous materials are useful for a wide variety of purposes. Some ofthe uses which may be mentioned by way of example are: waterpurlfication; purification of aqueous solutions containing sugarincluding sugar juices; purification of water from lead pipes; removalof heavy meta? ions from food, beverages and pharmaceutical products;decoiorization of solutions containing coloring matters, etc. Mycondensation products may also be employed to recover valuable metalcations from dilute solutions, e. g., gold from sea water, chromium fromchrome tanning liquors,

silver from photographic baths, etc. Another important application of mymaterials m in the absorption or adsorption of gases such as ammonia,the amines, e. g., triethyl amine, methyl amine, etc., from fluidmedia,either dissolved in a liquid or from vapors.

I claim:

1. In a. process for the preparation of a waterinsoluble syntheticresinous material having a capacity for exchanging cations in liquidmedia and obtained by a process including bringing about reactionbetween phenol, formaldehyde and an alkaline water-soluble salt ofsulfurous acid in relative molar proportions of 1:2 to 1:5, phenol:

formaldehyde, and of 1:025 to 1:1, phenolzsalt of sulfurous acid, andcuring the resulting product by heating, the improvement which comprisesbringing about the reaction in the presence of no more than 40% byweight of water and finally curing the resulting product at temperaturesof from C. to C.

2. A process for preparing a granular, waterinsoluble synthetic resinousmaterial having a capacity for exchanging cations in liquid media whichcomprises bringing about reaction between phenol, formaldehyde and analkaline watersoluble salt of sulfurous acid in relative molarproportions of 1:2 to 1:5, phenohformaldehyde, and of 1 :0.25 to 1:1,phenolzsalt of sulfurous acid, in the presence of no more than 40% byweight of water. finally curing the reaction product obtained by heatingat temperatures of from 125 C. to 175 0., and granulating the curedmaterial to a particle size of from 8-60 mesh.

-'3.Aprocessaccord1nztoc1aim2inwhich10% I to 40% by weight of water isinitially present in BEE mucus I m ti xt The toliowins referemes are ofrecord inthe 4. A process according to claim 2 in which the file of thispatent: reaction product is finally cured at 150 C. 5. A processaccording to claim 2 m which the UNHED Sums PATENTS reaction product isinitially cured at a tem- Number NW9 Date 1 perature 0! 100 C. and thenfinally cured at 21228359 wmenegger et 1941 1 o 150o C. Niederhfluser819 8.1. Sept 12,

HAROLD M. DAY. 10

